lesson05_future_exception.py

# SuperFastPython.com
# example of handling an exception raised within a task
from time import sleep
from concurrent.futures import ProcessPoolExecutor
from concurrent.futures import wait

# custom task function executed by a worker process
def work():
 # block a moment
 sleep(1)
 # raise an exception
 raise Exception('Something bad happened!')
 # never gets here

# protect the entry point
if __name__ == '__main__':
 # create a process pool
 with ProcessPoolExecutor() as exe:
 # execute our task
 future = exe.submit(work)
 # wait for the task to be done
 wait([future])
 # get the exception
 exception = future.exception()
 print(f'Task exception={exception}')
 # get the result from the task
 try:
 result = future.result()
 except Exception:
 print('Unable to get the result')